Describe how ACh transmits nerve impulses across Cholinergic Synapse
1.AP arrives at the presynaptic neurone2.AP stimulates voltage gated Ca ion channels to open3.Increased permeability of Ca ion channels causes synaptic vesicles to fuse with presynaptic membrane4. Exocytosis occurs - vesicles release neurotransmitter Acetylcholine (ACh) into synaptic cleft5. ACh diffuses across the synaptic cleft and binds to cholinergic receptors on the postsynaptic membrane6. Na ions channels open in the postsynaptic neurone7. Influx of Na ions causes depolarisation and if threshold is reached an AP8. Enzyme Acetylcholinesterase breaks down ACh so the response does not keep happening.
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